package com.heima.schedule.service.impl;

import com.alibaba.fastjson.JSON;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.heima.common.constants.ScheduleConstants;
import com.heima.common.redis.CacheService;
import com.heima.model.schedule.dtos.Task;
import com.heima.model.schedule.pojos.Taskinfo;
import com.heima.model.schedule.pojos.TaskinfoLogs;
import com.heima.schedule.mapper.TaskinfoLogsMapper;
import com.heima.schedule.mapper.TaskinfoMapper;
import com.heima.schedule.service.TaskService;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.PostConstruct;
import java.util.Calendar;
import java.util.Date;
import java.util.List;
import java.util.Set;

@Service
@Transactional
@Slf4j
public class TaskServiceImpl implements TaskService {
    /**
     * 添加延迟任务
     *
     * @param task
     * @return
     */
    @Override
    public long addTask(Task task) {
        //1.添加任务到数据库中

        boolean success = addTaskToDb(task);

        if (success) {
            //2.添加任务到redis
            addTaskToCache(task);
        }


        return task.getTaskId();
    }

    /**
     * 取消任务
     *
     * @param taskId
     * @return
     */
    @Override
    public boolean cancelTask(long taskId) {
        boolean flag = false;
        // 删除任务，更新任务日志态
        Task task = updateDB(taskId,ScheduleConstants.CANCELLED);

        // 删除redis的数据
        if (task!=null){
            removeTaskFromCache(task);
            flag = true;
        }

        return flag;
    }

    /**
     * 按照类型和优先级拉去任务
     *
     * @param type
     * @param priority
     * @return
     */
    @Override
    public Task poll(int type, int priority) {
        Task task = null;
        try {
            String key = type +"_"+priority;
            // 从redis中拉取数据
            String taskJson = cacheService.lRightPop(ScheduleConstants.TOPIC + key);
            if (StringUtils.isNotBlank(taskJson)){
                task = JSON.parseObject(taskJson, Task.class);

                // 修改数据库数据
                updateDB(task.getTaskId(),ScheduleConstants.EXECUTED);
            }
        } catch (Exception e) {
            log.error("poll task exception");
            e.printStackTrace();
        }
        // 修改数据库信息
        return task;
    }

    /**
     * 未来数据定时刷新--
     */
    @Scheduled(cron = "0 */1 * * * ?")
    public void refresh(){
        String token = cacheService.tryLock("FUTURE_TASK_SYNC", 1000 * 30);
        if (StringUtils.isNotBlank(token)){

            log.info("未来数据定时刷新--定时任务");
            // 获取所有未来数据的集合key
            Set<String> futureKeys = cacheService.scan(ScheduleConstants.FUTURE + "*");

            for (String futureKey : futureKeys) {
                //获取当前数据的key - topic
                String topicKey = ScheduleConstants.TOPIC + futureKey.split(ScheduleConstants.FUTURE)[1];
                // 按照Key和分值查找符合条件的数据
                Set<String> tasks = cacheService.zRangeByScore(futureKey, 0, System.currentTimeMillis());

                // 同步数据
                if(!tasks.isEmpty()){
                    cacheService.refreshWithPipeline(futureKey,topicKey,tasks);
                    log.info("成功的将:"+futureKey+" 刷新到了:"+topicKey);
                }
            }
        }
    }


    /**
     * 删除redis的数据
     * @param task
     */
    private void removeTaskFromCache(Task task) {
        String key = task.getTaskType() + "_" + task.getPriority();
        if (task.getExecuteTime() <= System.currentTimeMillis())
            cacheService.lRemove(ScheduleConstants.TOPIC + key ,0,JSON.toJSONString(task));
        else
            cacheService.zRemove(ScheduleConstants.FUTURE + key , JSON.toJSONString(task));
    }

    /**
     * 删除任务，更新任务日志态
     * @param taskId
     * @param status
     * @return
     */
    private Task updateDB(long taskId, int status) {
        Task task = null ;
        try {
            // 删除任务
            taskinfoMapper.deleteById(taskId);
            // 更新任务日志
            TaskinfoLogs taskinfoLogs = taskinfoLogsMapper.selectById(taskId);
            taskinfoLogs.setStatus(status);
            taskinfoLogsMapper.updateById(taskinfoLogs);
            task = new Task();
            BeanUtils.copyProperties(taskinfoLogs,task);
            task.setExecuteTime(taskinfoLogs.getExecuteTime().getTime());
        } catch (BeansException e) {
            e.printStackTrace();
            log.error("task cancel exception taskId={}",taskId);
        }
        return task;
    }

    @Autowired
    private CacheService cacheService;

    /**
     * 把任务添加到redis中
     *
     * @param task
     */
    private void addTaskToCache(Task task) {

        String key = task.getTaskType() + "_" + task.getPriority();

        //获取5分钟之后的时间  毫秒值
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MINUTE, 5);
        long nextScheduleTime = calendar.getTimeInMillis();

        //2.1 如果任务的执行时间小于等于当前时间，存入list
        if (task.getExecuteTime() <= System.currentTimeMillis()) {
            cacheService.lLeftPush(ScheduleConstants.TOPIC + key, JSON.toJSONString(task));
        } else if (task.getExecuteTime() <= nextScheduleTime) {
            //2.2 如果任务的执行时间大于当前时间 && 小于等于预设时间（未来5分钟） 存入zset中
            cacheService.zAdd(ScheduleConstants.FUTURE + key, JSON.toJSONString(task), task.getExecuteTime());
        }
    }

    @Autowired
    private TaskinfoMapper taskinfoMapper;

    @Autowired
    private TaskinfoLogsMapper taskinfoLogsMapper;

    /**
     * 添加任务到数据库中
     *
     * @param task
     * @return
     */
    private boolean addTaskToDb(Task task) {

        boolean flag = false;

        try {
            //保存任务表
            Taskinfo taskinfo = new Taskinfo();
            BeanUtils.copyProperties(task, taskinfo);
            taskinfo.setExecuteTime(new Date(task.getExecuteTime()));
            taskinfoMapper.insert(taskinfo);

            //设置taskID
            task.setTaskId(taskinfo.getTaskId());

            //保存任务日志数据
            TaskinfoLogs taskinfoLogs = new TaskinfoLogs();
            BeanUtils.copyProperties(taskinfo, taskinfoLogs);
            taskinfoLogs.setVersion(1);
            taskinfoLogs.setStatus(ScheduleConstants.SCHEDULED);
            taskinfoLogsMapper.insert(taskinfoLogs);

            flag = true;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return flag;
    }

    /**
     * 数据库任务定时同步到redis中
     */
    @PostConstruct
    @Scheduled(cron = "0 */5 * * * ?")
    public void reloadData(){
        // 清理缓存中的数据 list zset
        clearCache();

        // 查询符合条件的任务， 小于未来五分钟的数据
        //获取5分钟之后的时间  毫秒值
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MINUTE, 5);
        long nextScheduleTime = calendar.getTimeInMillis();
        List<Taskinfo> taskInfoList = taskinfoMapper.selectList(Wrappers.<Taskinfo>lambdaQuery().lt(Taskinfo::getExecuteTime, nextScheduleTime));

        // 把任务添加到redis
        if (taskInfoList != null && taskInfoList.size()>0){
            for (Taskinfo taskinfo : taskInfoList) {
                Task task = new Task();
                BeanUtils.copyProperties(taskinfo,task);
                task.setExecuteTime(taskinfo.getExecuteTime().getTime());
                addTaskToCache(task);
            }
        }
        log.info("数据库的任务同步到了redis");
    }

    public void clearCache(){
        Set<String> topicKeys = cacheService.scan(ScheduleConstants.TOPIC + "*");
        Set<String> futureKeys = cacheService.scan(ScheduleConstants.FUTURE + "*");
        cacheService.delete(topicKeys);
        cacheService.delete(futureKeys);
    }
}